Lower-thread control for chain-stitch machines.



A.-H. DE VOE. LOWER THREAD CONTROL FOR CHAIN STITCH MACHINES.

APPLICATION FILED AUGJZ' 19l6- Patented July 23 ALBERT H. mm von, or wnsrrrnnn, new J insnv, nssIenon Torr e siiveEre. almanac- I TUBING COMPANY, ACQBBORATiON or ivEw nnsnY;

retainer.

To all'whom it may concern:

Be it known that I, ALBERT I-I. citizen of the United States, residing at Westfield, in the county of Union and State of New Jersey, 3' have invented certain new and useful Improvements in LowerThread Controls for Ghain- Stitch Machines, of

which the followingis a specification, reference being had therein to the accompany Ling drawings. i

Myinvention relates to sewing machines and particularly to thread-controlling mechanismtherefor. i

The objectof my invention is to provide an improved thread-controlling device for the lower thread of atwo-thread chainstitch machine which is adapted to take up slack as the looper withdraws from the needle-loop, to maintain the thread substantially'free from slackas the looper nears the end of its. backward stroke and also tisit starts on its forward stroke up until it has entered the needle loop and finally to give up-thread'rapidly as the looper completes its forward movement. 1

Another object of my; invention is toprovide a thread control which accomplishes these results withoutdetracting from the compactness of a construction inwhich the looper and feed-actuating mechanisms are closely arranged on the main shaft below the cloth-plate of the machine.

To the attainment of these ends I have placed the take-up proper consisting of relatively fixed guide-eyes embracing two 1novable arms having angularly shaped slots intermediate-which arms is astationary incisioned plate, together with a thread-nipper and tension-diskson the frontof the vertical standard Ofthe frame. A pitm an within The invention is illustrated in the accom panying. drawings in which Figure 1 is a front side elevation of the machine. Fig. 2

. Specification of Letters Patent.

LOWER-THREAD colv'rnon Fen onlirfisrrircn MAoiiInns.

mama July as, rare.

Application filed August 12, 1916. Serial N 0. 114,503.

isan end elevatioinpartly insection, showing the pitman in its relation to the take-up and thread grip; Fig; 3 is fragmentary a detail showing the take-up arms at the be ginning of the take-up strokefl Fig. l the samea't the end of the take-up stroke. Fig.

5 the same when the thread is about to be l 1 gs. 6 and 7 are perspective views of thetake-up arms and "cooperating devices respectively; Fig. 8 is a detailed viewofthe connection between the pitman andne edlelever.

Themachine is of the two-thread chainstltch type in which a needle-bar 1 is actuatedthrough a needle-lever 2 pivoted con trally of an overhanging armas shown at2" and l driven from a pit1nan 38 to whichit is 1 connected by a ball-and-socket joint 3. -The pitman isactuated by an eccentric 4 Fig. 2

fixed to the main-shaft 5, about which it also osclllates as a center being. however inaintainedparallel to the pivot 2of the needlea lever 2 in all its movements through the agency of the stud 23 and slotted guiding 1 arm 24 and thereby prevented from rocking on its own longitudinal axis. The axis of the stud 23 1s parallel to the pivot 2 and passes through the center of the ball-and- For obtaining this socket connection 3. relatlve arrangementof members 23, 24 they are fixedly secured to the needle-lever 2 and p1tman'38 respectively in any suitable mandicated at 6 audits actuating'mechanism as well as the feed are very similar to that found in my prior Patent No. 1,107,659,

of the details of coiistructionjas their specific construction forms no part of the present i invention.

ner such as the screwand slot connection at .25 and the guideway at 26. The looper ingranted August 18,1914, and reference thereto may behad for a full understanding at its end nearest theloop er stationary cam-plate 10. This cam-plate has its upper portion 11 adjustably secured within a guide-way 12 in theblock in any suitable manner and has in its lower portion a V- U shaped incision 13. One side 131 ofthis incision isvertical and substantially straight, the other132 inclined upwardlythereto and slightly curved.) The purpose of this curvature is to delay the taking up action of the slotted arms to be hereinafter described until the looper is about to begin its rearward movement. Located vertically above the block is a thread-guarding arm indicated at 14 which shields the thread from the edges of material being operated upon. Journaled horizontally in the'block-is a rotatable pin 15 parallel to the main shaft 5. Extending.

A'rfiat spring 21 mounted upon the. lower.

surface of the block is adapted to always frictionally, engage the collar on the rockshaft and when in engagement, with a flat surface 22 of the collar the above mentioned U-shaped bar having the guiding eye is sub: stantially perpendicular.- The U-shaped bar 16 may be swung forwardly about its pivot.

to a substantially horizontal position to facilitate threading'of theeyel? and its angular relation to pin15 may be variedby adjusting the collar 19 through set-screw 20.

Secured, in any; suitable manner to. the lower end of the pitmanand extending-forwardly and upwardly out through an opening 40 in the vertical standard are two slot tedaarms 4141 which. embrace the incisioned plate 10 and are in .turn, embraced by the bar 16havingthe thread guiding eyelets. In the forward free ends of these arms are an-gularsshapedslots 42 which together with .theincision 13 in the plate and eyes 17 in theewire constitute the active portions of the. take-up.

Directly above theblock is a thread-gripping or nipping mechanism indicated generallyat 30 consisting of arigid base portion 31 fixed to the vertical standardand two spring-fingers 32, 33 secured to the base member .by means of a clamp screw 34:. The inner 32 of these two fingers carries spaced 'ears 35 between which the outer finger 33 is movable and defining therewith a thread passage which is adapted to be intermittently closed by the forward movement imparted, to a horizontally. arranged slide-pin 36 actuated from a bent arm 37 adjustably,

connected by the screw and slot 37 to the upper end of the needle-actuating pitman 38. This bentarm intermittently engages the 'slide-pinduring the operation of the machine thrusting the inner spring-finger of thethread-grippingdevice against the "outer spring-finger and thereby: gripping the threadwhenit is being taken up and at all other times leaving the thread free passage.

Mounted above the thread-gripping mechvertically downward to. the take-up through the eyelets; and slots. of which it is then passedtothe looper, isabout to be taken up by the upward and outward movement of the slotted. arms. This movement continues until the arms reach the position shown in Fig. lwhen. the taking up action is arrested and the arms continue their movement without any substantial. action on the thread until they have reached the position shown in Fig, 5. at which timethe thread slips from the bottom 43 of thetangular slot 42 in each take up arm up over the shoulder 4L4 into the horizontal portion; ofsaid slots thereby giving up thread rapidly and freely to the looper; which has just entered the needle loop.

action.

The. stud 23 and slotted guiding arm 24k are arranged as described in order to move slotted take-up armsi414l substantially in a plane and. parallel with. the incisioned plate 10. without wabbling,

Having thus set forth the nature of my invention, what I claim herein is 1. In a sewing machine, the combination of a main-shaft, means for takingv up and giving up thread, means for intermittently gripping the thread, and a common member movable bodily lengthwise for actuating each of said means.

2. I11 adouble-thread chain-stitch sewing machine, the combination with the needle and looper and their actuating mechanism including a main-shaft, of a looper threadcontrolling mechanism consisting of a takeup arm, thread-gripping means, a tension, andmeans including a needle-actuating element for actuating said take-up arm and thread-gripping means controlling the looper-thread.

3. Ina double-thread chain-stitch sewing machine, the combination with the needle and looper and their actuating mechanism, of a looper thread-controlling mechanism including a take-up arm, thread-gripping means, a tension, and a needle operatingpitman for actuating said take-up, arm and thread-gripping means.

4. In a lower-thread control, an incisioned plate, slotted take-up arms on opposite sides thereof, actuating means for the arms and guiding eyelets on opposite sides of said slotted take-up arms whereby the thread may be bent thrice during the taking up action.

5. In a looper-thread control for a doublechain-stitch machine, the combination of a plate provided with a substantially V-shaped incision, take-up arms on opposite sides of said plate having angular slots therein, and guiding eyes on opposite sides of said plate and beyond said take-up arms, and means for actuating said take-up arms.

6. In a lower-thread controlling mechanism, in combination, a vertically adjustable incisioned plate, slotted take-up arms, vertically and angularly adjustable guiding eyes, and means for moving said take-up arms in a substantially elliptical path whereby the looper-thread may be controlled.

7. In a lower-thread controlling mechanism, in combination, an incisioned plate, slotted take-up arms, thread-guiding eyes, said eyes being carried by a rotatable pin whereby they may be thrown forwardly for easy threading, and means frictionally restraining the rotation of said pin.

8. In a lower-thread controlling mechanism, in combination, an incisioned plate, slotted take-up arms, thread-guiding eyes, said eyes being carried by a rotatable pin whereby they may be thrown forwardly for easy threading, a collar having a fiat portion and being mounted on said pin, and means frictionally engaging said collar.

9. In a do'uble-chain-stitch machine, the combination of a needle, looper and actuating mechanism therefor including a needle actuating pitman, of a lower-thread control comprising take-up arms carried by the pitman and having angular-shaped slots inclosing .the looper-thread, an incisioned plate, and thread-guiding eyes cooperating therewith whereby thread is taken up as the looper retracts, maintained substantially free from slack while the looper is in its retracted position and until the looper moving forward has entered the needle-loop, and then liberated for furnishing slack to the looper as the looper completes its forward stroke.

10. In a thread-controlling mechanism for a two-thread chain-stitch machine, the combination with the needle, looper, and their actuating mechanism including a needleactuating pitman, of take-up arms fixed at one end to said pitman and free at the other end, said arms having thread-inclosing slots in their free ends, means arranged adjacent said slots and cooperating therewith to take up the thread as the looper is retracted to maintain the thread substantially free from Copies slack as the looper is in its retracted position until the looper moving forward has entered the needle-loop and finally give up the thread as the looper completes its forward motion.

11. In a lower-thread controlling mecha nism, the combination with a needle, looper and actuating mechanism therefor, and a frame, of a take-up mechanism, thread-gripping means arranged directly above said take-up mechanism, and a tension arranged directly above said thread-gripping means, said take-up, thread-grip and tension being operative externally of the frame whereby the thread passes from the tension to the take-up in a substantially straight line downwardly and from the take-up to the looper laterally in a substantially straight 12. In a lower thread control for chainstitch machines, the combination with stitching mechanism and actuating mechanism therefor including a pivoted needle-lever, a pitman connected thereto and a driving eccentric pivotally supporting said pitman, of take-up arms secured to said pitman adjacent said eccentric, and means for confining said take-up arms for movement in a fixed path substantially in a plane, said means being located adjacent the needle-lever.

13. In a lower thread control for chainstitch machines, the combination with stitch-' ing mechanism and actuating mechanism therefor including a pivoted needle-lever, a pitman connected thereto and a driving eccentric pivotally supporting said pitman, of take-up arms secured to said pitman adjacent said eccentric, and means for preventing the pitman from rocking appreciably about its own longitudinal axis to confine the movement of the take-up arms to a fixed path.

14. In a lower thread control for chainstitch machines, the combination with stitching mechanism and actuating mechanism therefor including a pivoted needle-lever, a pitman connected thereto by a ball-andsocket joint and a driving eccentric piv otally supporting said pitman, of take-up arms secured to said pitman adjacent said eccentric, and means for preventing the pitman from rocking appreciably about its own longitudinal axis to confine the movement of the take-up arms to a fixed path, said means including a pin, the axis of which is parallel to the pivotal axis of the needle-lever and passes through the center of the ball-andsocket connection between the needle-lever and pitman.

In testimony whereof, I have signed my name to this specification.

ALBERT 'H. DE VOE.

of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. 

